Various methods for encrypted data transmission are known from the prior art. Basically a distinction is made in this field between asymmetrical and symmetrical encryption methods.
Symmetrical encryption methods are also referred to as “private key” encryption. With a symmetrical encryption method, the users taking part in the communication have the same secret key, which is used both for the encryption and for the decryption. Examples of symmetrical encryption methods known from the prior art are DES, Triple DES, RC2, RC4, IDEA, and Skipjack.
A common disadvantage of symmetrical encryption methods known from the prior art is that the symmetrical keys must be transmitted to the individual users before the encrypted communication starts, with the possibility that said transmission can be intercepted.
With asymmetrical encryption methods, which are also referred to as “public key” encryption, a public key is used for the encryption. The data encrypted using the public key of a user can only be decrypted using the secret private key of said user. Known a symmetrical encryption methods are Diffie-Hellmann and RSA.